Insituform Technologies Inc. v. CAT Contracting Inc.
385 F.3d 1360, 72 USPQ2d 1870 (Fed. Cir. 2004)
Facts
The Federal Circuit affirmed a judgment of infringement under the Doctrine of Equivalents, and held that plaintiff Insituform had rebutted the presumption of a complete bar on application of the doctrine. Plaintiff Insituform pioneered a method for repairing underground sewer pipes. It owns U.S. Patent No. 4,366,012, directed to installing a liner into the pipe. As originally filed, claim 1 did not limit a number of cups that could be used to create a vacuum. But it was amended and limited to one cup during prosecution. Defendant CAT is a sewer rehabilitation company which uses a "multiple cup" process of tube liner impregnation that does not literally infringe claim 1.
Rules and Analysis
The Fed. Circuit summarized the three ways from Festo III in which a presumption that a narrowing amendment made for a reason of patentability surrenders the entire territory between the original and amended claim limitation can be rebutted:
- The patentee may demonstrate that the alleged equivalent would have been unforeseeable at the time of the narrowing amendment;
- The patentee may demonstrate that the rationale underlying the narrowing amendment bore no more than a tangential relation to the equivalent in question; or
- There may be "some other reason suggesting that the patentee could not reasonably have been expected to have described the alleged equivalent."
In this case, the prosecution history establishes "the rationale underlying" the amendment narrowing the scope of literal claim coverage from multiple cups to a single cup bears no more than a tangential relation to the equivalent in question. There is no indication in the prosecution history of any relationship between the narrowing amendment and a multiple cup process, which is the alleged equivalent. Thus, Insituform rebutted the Festo presumption. The amendment limiting the literal scope of claim 1 bears only a tangential relation to the equivalent in question.